Desk lamp



FIG. 1 is a right side elevational view of a desk lamp showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The adjustable arm is shown in broken lines for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a desk lamp, as shown and described. 